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    <meta charset="UTF-8">
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    <title>Document</title>
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<body>
    <h1>服务器要主动推送消息给我哦</h1>

    <script>
        var ws = new WebSocket('ws://localhost:8080');
        ws.onopen = function() {
            console.log('ws onopen');
            ws.send('from client:hello');
        }

        ws.onmessage = function(e) {
            console.log('ws message');
            console.log('from server:' + e.data);
        }
    </script>
</body>
</html>